Michael Faraday The English chemist and physicist Michael Faraday, b. Sept. 22, 1791, d. Aug. 25, 1867, is known for his pioneering experiments in electricity and magnetism. Many consider him the greatest experimentalist who ever lived. Several concepts that he derived directly from experiments, such as lines of magnetic force, have become common ideas in modern physics. Faraday was born at Newington, Surrey, near London. He received little more than a primary education, and at the age of 14 he was apprenticed to a bookbinder. There he became interested in the physical and chemical works of the time. After hearing a lecture by the famous chemist Humphry Davy, he sent Davy the notes he had made of his lectures. As a result Faraday was appointed, at the age of 21, assistant to Davy in the laboratory of the Royal Institution in London. During the initial years of his scientific work, Faraday occupied himself mainly with chemical problems. He discovered two new chlorides of carbon and succeeded in liquefying chlorine and other gases.

He isolated benzene in 1825, the year in which he was appointed director of the laboratory. Davy, who had the greatest influence on Faraday's thinking, had shown in 1807 that the metals sodium and potassium can be precipitated from their compounds by an electric current, a process known as electrolysis. Faraday's vigorous pursuit of these experiments led in 1834 to what became known as Faraday's laws of electrolysis. Faraday's research into electricity and electrolysis was guided by the belief that electricity is only one of the many manifestations of the unified forces of nature, which included heat, light, magnetism, and chemical affinity. Although this idea was erroneous, it led him into the field of electromagnetism, which was still in its infancy. In 1785, Charles Coulomb had been the first to demonstrate the manner in which electric charges repel one another, and it was not until 1820 that Hans Christian Oersted and Andre Marie Ampere discovered that an electric current produces a magnetic field.

Faraday's ideas about conservation of energy led him to believe that since an electric current could cause a magnetic field, a magnetic field should be able to produce an electric current. He demonstrated this principle of induction in 1831. Faraday expressed the electric current induced in the wire in terms of the number of lines of force that are cut by the wire. The principle of induction was a landmark in applied science, for it made possible the dynamo, or generator, which produces electricity by mechanical means. Faraday's introduction of the concept of lines of force was rejected by most of the mathematical physicists of Europe, since they assumed that electric charges attract and repel one another, by action at a distance, making such lines unnecessary. Faraday had demonstrated the phenomenon of electromagnetism in a series of experiments, however. This experimental necessity probably led the physicist James Clerk Maxwell to accept the concept of lines of force and put Faraday's ideas into mathematical form, thus giving birth to modern field theory. Faraday's discovery (1845) that an intense magnetic field can rotate the plane of polarized light is known today as the Faraday effect. The phenomenon has been used to elucidate molecular structure and has yielded information about galactic magnetic fields.

Faraday described his numerous experiments in electricity and electromagnetism in three volumes entitled Experimental Researches in Electricity (1839, 1844, 1855); his chemical work was chronicled in Experimental Researches in Chemistry and Physics (1858). Faraday ceased research work in 1855 because of declining mental powers, but he continued as a lecturer until 1861. A series of six children's lectures published in 1860 as The Chemical History of a Candle, has become a classic of science literature. Faraday | Define Faraday at Dictionary.com Faraday [far-uh-dee, -dey] /ˈfær ə di, -ˌdeɪ/ Spell Michael, 1791–1867, English physicist and chemist: discoverer of electromagnetic induction. 2. a unit of electricity used in electrolysis, equal to 96,500 coulombs.

Dictionary.com Unabridged Examples from the Web for Faraday Expand Historical Examples So it is said of Faraday by Professor Tyndall, that "pretence of all kinds, whether in life or in philosophy, was hateful to him." Aether and Gravitation William George Hooper Faraday had shown that electromotive force depends on chemical affinity. British Dictionary definitions for Faraday Expand noun 1. a quantity of electricity, used in electrochemical calculations, equivalent to unit amount of substance of electrons. It is equal to the product of the Avogadro number and the charge on the electron and has the value 96 487 coulombs per mole F Word Origin C20: named after Michael Faraday Faraday noun 1. Michael. 1791–1867, English physicist and chemist who discovered electromagnetic induction, leading to the invention of the dynamo. He also carried out research into the principles of electrolysis Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd.

1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 faraday far·a·day (fār'ə-dā') n. The electric charge required to deposit or liberate 1 gram equivalent weight of a substance in electrolysis, approximately 9.6494 × 104 coulombs. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company. faraday (fār'ə-dā') A measure of electric charge equal to the charge carried by one mole of electrons, about 96,494 coulombs per mole. The faraday is used in measurements of the electricity required to break down a compound by electrolysis.

Faraday (fār'ə-dā', -dē) British physicist and chemist whose experiments into the connections between electricity, magnetism, and light laid the foundation for modern physics. In addition to discovering electromagnetic induction, he invented the electric motor, generator, and transformer, and he discovered the carbon compound benzene. Our Living Language : The nineteenth century saw rapid growth in the understanding of electricity and magnetism, and much of this progress was due to Michael Faraday. There was no hint from his humble beginnings that he was to become a great scientist. Born in 1791, the son of an English blacksmith, Faraday received little formal schooling. At 14 he was apprenticed to a bookbinder, and it was during this time that he developed an interest in science. In 1812 he attended a series of lectures by Humphry Davy, the well-known chemist. Later in the year, Faraday sent Davy his notes on the talks, asking to become his assistant. When an opening became available, Davy took him on.

Faraday, a truly gifted experimenter, started amassing an impressive body of work, converting electrical into mechanical energy (1821), liquefying chlorine (1823), and isolating benzene (1825). He made perhaps his greatest discovery—electromagnetic induction—in 1831, when he produced electricity from magnetism by moving a magnet inside a wire coil. Faraday also came up with the concept of electric and magnetic fields. When James Clerk Maxwell put Faraday's ideas into mathematical form (Faraday knew little mathematics), they became a cornerstone of physics. It was Faraday's research that helped transform electricity from a scientific curiosity into a workable technology. But he also transformed the language, helping to coin the words anode, cathode, ion, and electrode, among others. It is only fitting that there are now two words named after him: farad, the unit of capacitance, and faraday, a unit used to measure the amount of electrical charge. The American Heritage® Science Dictionary Copyright © 2002. Published by Houghton Mifflin. All rights reserved. Who Discovered Electromagnetism?

- Science and Inventions Science and Inventions Leave a comment Electromagnetism is one of the great powers that human use everyday in several uses. In the year 1812, Michael Faraday (1791-1867) the English chemist and physicist was able to reach for the fact of the electromagnetic field. In the year 1820, Hans Christian Ørsted (1777-1851) the Danish chemist and physicist was able to reach for a great discovery that the magnetic current are a result of the electric current. He reached that conclusion when he noticed that the compass needle get distracted when exposed to electric current. André-Marie Ampère (1775-1836) the French mathematician and physicist that was able to figure out the amper, the measuring unit of electricity. In the year 1820, after few days from Hans Christian Ørsted discovery, Ampère had reached to the same relation between electricity and magnetism.

In the year 1832, Hippolyte Pixii (1808-1835) a French machines maker used the concepts of Michael Faraday and was able to manufacture the Dynamo. The Dynamo convert mechanical rotation to electricity depending on the electromagnetic theory. In the year 1873, James Clerk Maxwell (1831-1879) the Scottish mathematician and physicist was able to combine electricity with magnetism along with the light in a theory. He reached that all of electric, magnetism and light fields travel through space in the form of waves. In the year 1886, Heinrich Rudolf Hertz (1857-1894) the German physicist, he explained and proved the electromagnetic waves that James Clerk Maxwell suggested. In the year 1905, Albert Einstein (1879-1955) the famous German-American physicist reached for the special theory of relativity. invented the first electric motor and dynamo | nitum Biography of Michael Faraday Standard English physicist and chemist whose many experiments contributed greatly to the understanding of electromagnetism.

Faraday, who became one of the greatest scientists of the 19th century, began hiscareer as a chemist. Many consider him the greatest experimentalist who ever lived. Several concepts that he derived directly from experiments, such as lines of magnetic force, have become common ideas in modern physics. He wrote a manual of practical chemistry that reveals his mastery of the technical aspects of his art, discovered a number of new organic compounds, among them benzene, and was the first to liquefy a “permanent” gas (i.e., one that was believed to be incapable of liquefaction). His major contribution, however, was in the field of electricity and magnetism. He was the first to produce an electric current from a magnetic field, invented the first electric motor and dynamo, demonstrated the relation between electricity and chemical bonding, discovered the effect of magnetism on light, and discovered and named diamagnetism, the peculiar behaviour of certain substances in strong magnetic fields. He provided the experimental, and a good deal of the theoretical, foundation upon which James Clerk Maxwell erected classicalelectromagnetic field theory. He introduced several words that we still use today to discuss electricity: ion, electrode, cathode, and anode.

Early life: Michael Faraday was born on Sept. 22, 1791 in a poor and very religious family in the country village of Newington, Surrey, now a part of South London. His father was a blacksmith who had migrated from the north of England earlier in 1791 to look for work. His mother was a country woman of great calm and wisdom who supported her son emotionally through a difficult childhood. Faraday was one of four children, all of whom were hard put to get enough to eat, since their father was often ill and incapable of working steadily. Faraday later recalled being given one loaf of bread that had to last him for a week. The family belonged to a small Christian sect, called Sandemanians, that provided spiritual sustenance to Faraday throughout his life. It was the single most important influence upon him and strongly affected the way in which he approached and interpreted nature. Faraday himself, shortly after his marriage, at the age of thirty, joined the same sect, to which he adhered till his death. Religion and science he kept strictly apart, believing that the data of science were of an entirely different nature from the direct communications between God and the soul on which his religious faith was based.

Faraday received only the rudiments of an education, learning to read, write, and cipher in a church Sunday school. At an early age he began to earn money by delivering newspapers for a book dealer and bookbinder, and at the age of 14 he was apprenticed to the man. Unlike the other apprentices, Faraday took the opportunity to read some of the books brought in for rebinding. The article on electricity in the third edition of the Encyclopadia Britannica particularly fascinated him. Using old bottles and lumber, he made a crude electrostatic generator and did simple experiments. He also built a weak voltaic pile with which he performed experiments in electrochemistry. He was also among other young Londoners who persued an interest in science by gathering to hear talks at the City Philosophical Society. Faraday’s great opportunity came when he was offered a free ticket to attend chemical lectures by Sir Humphry Davy at the Royal Institution of Great Britain in London. Faraday went, sat absorbed with it all, recorded the lectures in his notes, and returned to bookbinding with the seemingly unrealizable hope of entering the temple of science.

He sent a bound copy of his notes to Davy along with a letter asking foremployment, but there was no opening. Davy did not forget, however, and, when one of his laboratory assistants was dismissed for brawling, he offered Faraday a job. His first assignment was to accompany Sir Humphry and his wife on a tour of the Continent, during which he sometimes had to be a personal servant to Lady Davy. Then Faraday began as Davy’s laboratory assistant and learned chemistry at the elbowof one of the greatest practitioners of the day. It has been said, with some truth, that Faraday was Davy’s greatest discovery. When Faraday joined Davy in 1812, Davy was in the process of revolutionizing the chemistry of the day. Antoine-Laurent Lavoisier, the Frenchman generally credited with founding modern chemistry, had effected his rearrangement of chemical knowledge in the 1770s and 1780s by insisting upon a few simple principles. Among these was that oxygen was a unique element, in that it was the only supporter of combustion and was also the element that lay at the basis of all acids.

Davy, after having discovered sodium and potassium by using a powerful current from a galvanic battery to decompose oxides of these elements, turned to the decomposition of muriatic (hydrochloric) acid, one of the strongest acids known. The products of the decomposition were hydrogen and a green gas that supported combustion and that, when combined with water, produced an acid. Davy concluded that this gas was an element, to which he gave the name chlorine, and that there was no oxygen whatsoever in muriatic acid. Acidity, therefore, was not the result of the presence of an acid-forming element but of some other condition. What else could that condition be but the physical form of the acid molecule itself? Davy suggested, then, that chemical properties were determined not by specific elements alone but also by the ways in which these elements were arranged in molecules. In arriving at this view he was influenced by an atomic theory that was also to have important consequences for Faraday’s thought. This theory, proposed in the 18th century by Ruggero Giuseppe Boscovich, argued that atoms were mathematical points surrounded by alternating fields of attractive and repulsive forces.

A true element comprised a single such point, and chemical elements were composed of a number of such points, about which the resultant force fields could be quite complicated. Molecules, in turn, were built up of these elements, and the chemical qualities of both elements and compounds were the results of the final patterns of force surrounding clumps of point atoms. One property of such atoms and molecules should be specifically noted: they can be placed under considerable strain, or tension, before the “bonds” holding them together are broken. These strains were to be central to Faraday’s ideas about electricity. Faraday’s second apprenticeship, under Davy, came to an end in 1820. By then he had learned chemistry as thoroughly as anyone alive. He had also had ample opportunity to practice chemical analyses and laboratory techniques to the point of complete mastery, and he had developed his theoretical views to the point that they could guide him in his researches. There followed a series of discoveries that astonished the scientific world. Michael Faraday Engraving after an original work by Charles Turner (1773-1857) Faraday achieved his early renown as a chemist. As his chemical capabilities increased, he was given more responsibility.

In 1825 he replaced the seriously ailing Davy in his duties directing the laboratory at the Royal Institution. In 1833 he was appointed to the Fullerian Professorship of Chemistry-a special research chair created for him. His reputation as an analytical chemist led to his being called as an expert witness in legal trials and to the building up of a clientele whose fees helped to support the Royal Institution. In 1820 he produced the first known compounds of carbon and chlorine, C2Cl6 and C2Cl4. These compounds were produced by substituting chlorine for hydrogen in “olefiant gas” (ethylene), the first substitution reactions induced. (Such reactions later would serve to challenge the dominant theory of chemical combination proposed by Jons Jacob Berzelius.) In 1825, as a result of research on illuminating gases, Faraday isolated and described benzene. In the 1820s he also conducted investigations of steel alloys, helping to lay the foundations for scientific metallurgy and metallography.

While completing an assignment from the Royal Society of London to improve the quality of optical glass for telescopes, he produced a glass of very high refractive index that was to lead him, in 1845, to the discovery of diamagnetism. In 1821 he married Sarah Barnard, settled permanently at the Royal Institution, and began the series of researches on electricity and magnetism that was to revolutionize physics. Faraday announcing his discovery to his wife on Christmas morning, 1821 (from “Electricity in Daily Life”, C.F. Brackett et al., 1890) Michael Faraday with his wife Sarah Faraday’s research into electricity and electrolysis was guided by the belief that electricity is only one of the many manifestations of the unified forces of nature, which included heat, light, magnetism, and chemical affinity. Although this idea was erroneous, it led him into the field of electromagnetism, which was still in its infancy.

In 1785, Charles Coulomb had been the first to demonstrate the manner in which electric charges repel one another, and it was not until 1820 that Hans Christian Oersted and Andre Marie Ampere discovered that an electric current produces a magnetic field. Faraday’s ideas about conservation of energy led him to believe that since an electric current could cause a magnetic field, a magnetic field should be able to produce an electric current. He demonstrated this principle of induction in 1831. Faraday expressed the electric current induced in the wire in terms of the number of lines of force that are cut by the wire. The principle of induction was a landmark in applied science, for it made possible the dynamo, or generator, which produces electricity by mechanical means. Faraday’s introduction of the concept of lines of force was rejected by most of the mathematical physicists of Europe, since they assumed that electric charges attract and repel one another, by action at a distance, making such lines unnecessary. Faraday had demonstrated the phenomenon of electromagnetism in a series of experiments, however.

Faraday’s descriptive theory of lines of force moving between bodies with electrical and magnetic properties enabled James Clerk Maxwell to formulate an exact mathematical theory of the propagation of electromagnetic waves. In 1865, Maxwell proved mathematically that electromagnetic phenomena are propagated as waves through space with the velocity of light, thereby laying the foundation of radio communication confirmed experimentally in 1888 by Hertz and developed for practical use by Guglielmo Marconi at the turn of the century. In 1820 Hans Christian Orsted had announced the discovery that the flow of an electric current through a wire produced a magnetic field around the wire. Andre-Marie Ampere showed that the magnetic force apparently was a circular one, producing in effect a cylinder of magnetism around the wire. No such circular force had ever before been observed, and Faraday was the first to understand what it implied. If a magnetic pole could be isolated, it ought to move constantly in a circle around a current-carrying wire. Faraday’s ingenuity and laboratory skill enabled him to construct an apparatus that confirmed this conclusion. This device, which transformed electrical energy into mechanical energy, was the first electric motor. This discovery led Faraday to contemplate the nature of electricity.

Unlike his contemporaries, he was not convinced that electricity was a material fluid that flowed through wires like water through a pipe. Instead, he thought of it as a vibration or force that was somehow transmitted as the result of tensions created in the conductor. One of his first experiments after his discovery of electromagnetic rotation was to pass a ray of polarized light through a solution in which electrochemical decomposition was taking place in order to detect the intermolecular strains that he thought must be produced by the passage of an electric current. During the 1820s he kept coming back to this idea, but always without result. In the spring of 1831 Faraday began to work with Charles (later Sir Charles) Wheatstone on the theory of sound, another vibrational phenomenon. He was particularly fascinated by the patterns (known as Chladni figures) formed in light powder spread on iron plates when these plates were thrown into vibration by a violin bow. Here was demonstrated the ability of a dynamic cause to create a static effect, something he was convinced happened in a current-carrying wire. He was even more impressed by the fact that such patterns could be induced in one plate by bowing another nearby.

Such acoustic induction is apparently what lay behind his most famous experiment. On August 29, 1831, Faraday wound a thick iron ring on one side with insulated wire that was connected to a battery. He then wound the opposite side with wire connected to a galvanometer. What he expected was that a “wave” would be produced when the battery circuit was closed and that the wave would show up as a deflection of the galvanometer in the second circuit. He closed the primary circuit and, to his delight and satisfaction, saw the galvanometer needle jump. A current had been induced in the secondary coil by one in the primary. When he opened the circuit, however, he was astonished to see the galvanometer jump in the opposite direction. Somehow, turning off the current also created an induced current in the secondary circuit, equal and opposite to the original current. This phenomenon led Faraday to propose what he called the “electrotonic” state of particles in the wire, which he considered a state of tension. A current thus appeared to be the setting up of such a state of tension or the collapse of such a state.

Although he could not find experimental evidence for the electrotonic state, he never entirely abandoned the concept, and it shaped most of his later work. In the fall of 1831 Faraday attempted to determine just how an induced current was produced. His original experiment had involved a powerful electromagnet, created by the winding of the primary coil. He now tried to create a current by using a permanent magnet. He discovered that when a permanent magnet was moved in and out of a coil of wire a current was induced in the coil. Magnets, he knew, were surrounded by forces that could be made visible by the simple expedient of sprinkling iron filings on a card held over them. Faraday saw the “lines of force” thus revealed as lines of tension in the medium, namely air, surrounding the magnet, and he soon discovered the law determining the production of electric currents by magnets: the magnitude of the current was dependent upon the number of lines of force cut by the conductor in unit time. He immediately realized that a continuous current could be produced by rotating a copper disk between the poles of a powerful magnet and taking leads off the disk’s rim and centre.

The outside of the disk would cut more lines than would the inside, and there would thus be a continuous current produced in the circuit linking the rim to the centre. This was the first dynamo. It was also the direct ancestor of electric motors, for it was only necessary to reverse the situation, to feed an electric current to the disk, to make it rotate. On 29th August 1831, using his “induction ring”, Faraday made one of his greatest discoveries – electromagnetic induction: the “induction” or generation of electricity in a wire by means of the electromagnetic effect of a current in another wire. The induction ring was the first electric transformer. In a second series of experiments in September he discovered magneto-electric induction: the production of a steady electric current. To do this, Faraday attached two wires through a sliding contact to a copper disc. By rotating the disc between the poles of a horseshoe magnet he obtained a continuous direct current. This was the first generator. Although neither of Faraday’s devices is of practical use today they enhanced immeasurably the theoretical understanding of electricity and magnetism.

He described these experiments in two papers presented to the Royal Society on 24th November 1831, and 12th January 1832. These were the first and second parts of his “Experimental researches into electricity” in which he gave his “law which governs the evolution of electricity by magneto-electric induction”. After reading this, a young Frenchman, Hippolyte Pixii, constructed an electric generator that utilized the rotary motion between magnet and coil rather than Faraday’s to and fro motion in a straight line. All the generators in power stations today are direct descendants of the machine developed by Pixii from Faraday’s first principles. It was characteristic of Faraday’s devotion to the enlargement of the bounds of human knowledge that on his discovery of magneto-electricity he abandoned the commercial work by which he had added to his small salary, in order to reserve all his energies for research. This financial loss was in part made up later by a pension of 300 pounds a year from the British Government. Theory of electrochemistry: While Faraday was performing these experiments and presenting them to the scientific world, doubts were raised about the identity of the different manifestations of electricity that had been studied.

Were the electric “fluid” that apparently was released by electric eels and other electric fishes, that produced by a static electricity generator, that of the voltaic battery, and that of the new electromagnetic generator all the same? Or were they different fluids following different laws? Faraday was convinced that they were not fluids at all but forms of the same force, yet he recognized that this identity had never been satisfactorily shown by experiment. For this reason he began, in 1832, what promised to be a rather tedious attempt to prove that all electricities had precisely the same properties and caused precisely the same effects. The key effect was electrochemical decomposition. Voltaic and electromagnetic electricity posed no problems, but static electricity did. As Faraday delved deeper into the problem, he made two startling discoveries. First, electrical force did not, as had long been supposed, act at a distance upon chemical molecules to cause them to dissociate. It was the passage of electricity through a conducting liquid medium that caused the molecules to dissociate, even when the electricity merely discharged into the air and did not pass into a “pole” or “centre of action” in a voltaic cell.

Second, the amount of the decomposition was found to be related in a simple manner to the amount of electricity that passed through the solution. These findings led Faraday to a new theory of electrochemistry. The electric force, he argued, threw the molecules of a solution into a state of tension (his electrotonic state). When the force was strong enough to distort the fields of forces that held the molecules together so as to permit the interaction of these fields with neighbouring particles, the tension was relieved by the migration of particles along the lines of tension, the different species of atoms migrating in opposite directions. The amount of electricity that passed, then, was clearly related to the chemical affinities of the substances in solution. These experiments led directly to Faraday’s two laws of electrochemistry: (1) The amount of a substance deposited on each electrode of an electrolytic cell is directly proportional to the quantity of electricity passed through the cell. (2) The quantities of different elements deposited by a given amount of electricity are in the ratio of their chemical equivalent weights. Michael Faraday (1841/42) Faraday’s work on electrochemistry provided him with an essential clue for the investigation of static electrical induction.

Since the amount of electricity passed through the conducting medium of an electrolytic cell determined the amount of material deposited at the electrodes, why should not the amount of electricity induced in a nonconductor be dependent upon the material out of which it was made? In short, why should not every material have a specific inductive capacity? Every material does, and Faraday was the discoverer of this fact. The portrate shown here was painted by Thomas Phillips (1770-1845), oil on canvas, The National Portrait Gallery, London. Michael Faraday (ca. 1844-60) By 1839 Faraday was able to bring forth a new and general theory of electrical action. Electricity, whatever it was, caused tensions to be created in matter. When these tensions were rapidly relieved (i.e., when bodies could not take much strain before “snapping” back), then what occurred was a rapid repetition of a cyclical buildup, breakdown, and buildup of tension that, like a wave, was passed along the substance. Such substances were called conductors.

In electrochemical processes the rate of buildup and breakdown of the strain was proportional to the chemical affinities of the substances involved, but again the current was not a material flow but a wave pattern of tensions and their relief. Insulators were simply materials whose particles could take an extraordinary amount of strain before they snapped. Electrostatic charge in an isolated insulator was simply a measure of this accumulated strain. Thus, all electrical action was the result of forced strains in bodies. The strain on Faraday of eight years of sustained experimental and theoretical work was too much, and in 1839 his health broke down. For the next six years he did little creative science. Not until 1845 was he able to pick up the thread of his researches and extend his theoretical views. Michael Faraday (ca. 1849) lithograph by W. Bosley from A. F. J. Claudet daguerreotype Smithsonian Archives Faraday had scientific discussions and collaborations with many famous scientists of his time.

Group of scientists: (from left to right) English physicist and chemist Michael Faraday (1791 – 1867), English biologist Thomas Huxley (1825 – 1895), English physicist Sir Charles Wheatley (1802 – 1875), Scottish physicist Sir David Brewster (1781 – 1868) and Irish physicist John Tyndall (1820 – 1893). Later life: Since the very beginning of his scientific work, Faraday had believed in what he called the unity of the forces of nature. By this he meant hat all the forces of nature were but manifestations of a single universal force and ought, therefore, to be convertible into one another. In 1846 he made public some of the speculations to which this view led him. A lecturer, scheduled to deliver one of the Friday evening discourses at the Royal Institution by which Faraday encouraged the popularization of science, panicked at the last minute and ran out, leaving Faraday with a packed lecture hall and no lecturer.

On the spur of the moment, Faraday offered “Thoughts on Ray Vibrations.” Specifically referring to point atoms and their infinite fields of force, he suggested that the lines of electric and magnetic force associated with these atoms might, in fact, serve as the medium by which light waves were propagated. Many years later, Maxwell was to build his electromagnetic field theory upon this speculation. Professor Faraday delivering a lecture at the Royal Institution. Members of the Royal Instsitution attend a lecture given by Professor Faraday on Magnetism and Light, London 1846. Inventor and scientist Michael Faraday lectures at the Royal Institution. The Prince Consort with his sons the Prince of Wales and the Duke of Edinburgh are seated in the front row facing Faraday. From a painting by Alexander Blaikley. Every year on Christmas Day, he presented his Faraday Lectures for Children which were crowded with interested listeners. The Royal Institution Christmas lectures for children, begun by Faraday, continue to this day.

Faraday described his numerous experiments in electricity and electromagnetism in three volumes entitled Experimental Researches in Electricity (1839, 1844, 1855); his chemical work was chronicled in Experimental Researches in Chemistry and Physics (1858). Faraday ceased research work in 1855 because of declining mental powers, but he continued as a lecturer until 1861. A series of six children’s lectures published in 1860 as The Chemical History of a Candle, has become a classic of science literature. When Faraday returned to active research in 1845, it was to tackle again a problem that had obsessed him for years, that of his hypothetical electrotonic state. He was still convinced that it must exist and that he simply had not yet discovered the means for detecting it. Once again he tried to find signs of intermolecular strain in substances through which electrical lines of force passed, but again with no success. It was at this time that a young Scot, William Thomson (later Lord Kelvin), wrote Faraday that he had studied Faraday’s papers on electricity and magnetism and that he, too, was convinced that some kind of strain must exist.

He suggested that Faraday experiment with magnetic lines of force, since these could be produced at much greater strengths than could electrostatic ones. Faraday took the suggestion, passed a beam of plane-polarized light through the optical glass of high refractive index that he had developed in the 1820s, and then turned on an electromagnet so that its lines of force ran parallel to the light ray. This time he was rewarded with success. The plane of polarization was rotated, indicating a strain in the molecules of the glass. But Faraday again noted an unexpected result. When he changed the direction of the ray of light, the rotation remained in the same direction, a fact that Faraday correctly interpreted as meaning that the strain was not in the molecules of the glass but in the magnetic lines of force. The direction of rotation of the plane of polarization depended solely upon the polarity of the lines of force; the glass served merely to detect the effect. Faraday’s discovery (1845) that an intense magnetic field can rotate the plane of polarized light is known today as the Faraday effect. The phenomenon has been used to elucidate molecular structure and has yielded information about galactic magnetic fields.

This discovery confirmed Faraday’s faith in the unity of forces, and he plunged onward, certain that all matter must exhibit some response to a magnetic field. To his surprise he found that this was in fact so, but in a peculiar way. Some substances, such as iron, nickel, cobalt, and oxygen, lined up in a magnetic field so that the long axes of their crystalline or molecular structures were parallel to the lines of force; others lined up perpendicular to the lines of force. Substances of the first class moved toward more intense magnetic fields; those of the second moved toward regions of less magnetic force. Faraday named the first group paramagnetics and the second diamagnetics. After further research he concluded that paramagnetics were bodies that conducted magnetic lines of force better than did the surrounding medium, whereas diamagnetics conducted them less well. By 1850 Faraday had evolved a radically new view of space and force. Space was not “nothing,” the mere location of bodies and forces, but a medium capable of supporting the strains of electric and magnetic forces. The energies of the world were not localized in the particles from which these forces arose but rather were to be found in the space surrounding them. Thus was born field theory.

As Maxwell later freely admitted, the basic ideas for his mathematical theory of electrical and magnetic fields came from Faraday; his contribution was to mathematize those ideas in the form of his classical field equations. Michael Faraday’s concern about contemporary environmental concerns caricatured. A cartoon depicting English chemist and physicist Professor Michael Faraday holding his nose from a smell as he gives his card to ‘Father Thames’. From about 1855, Faraday’s mind began to fail. He still did occasional experiments, one of which involved attempting to find an electrical effect of raising a heavy weight, since he felt that gravity, like magnetism, must be convertible into some other force, most likely electrical. This time he was disappointed in his expectations, and the Royal Society refused to publish his negative results. More and more, Faraday began to sink into senility. Queen Victoria rewarded his lifetime of devotion to science by granting him the use of a house at Hampton Court and even offered him the honour of a knighthood. Faraday gratefully accepted the cottage but rejected the knighthood; he would, he said, remain plain Mr. Faraday to the end.

In contrast to Davy, Faraday was known throughout his life as a kind and humble person, unconcerned with honors and eager to practice his science to the best of his ability. In 1865, Faraday ended his connection with the Royal Institution after over 50 years of service. He died at his house at Hampton Court on 25th August 1867 and was buried in Highgate Cemetery, London, leaving as his monument a new conception of physical reality. His discoveries have had an incalculable effect on subsequent scientific and technical development. He was a true pioneer of scientific discovery. The discoveries made by Faraday were so numerous, and often demand so detailed a knowledge of chemistry and physics before they can be understood, that it is impossible to attempt to describe or even enumerate them here. Among the most important are the discovery of magneto-electric induction, of the law of electro-chemical decomposition, of the magnetization of light, and of diamagnetism.

Round each of these are grouped numbers of derivative but still highly important additions to scientific knowledge, and together they form so vast an achievement as to lead his successor, Tyndall, to say, “Taking him for all and all, I think it will be conceded that Michael Faraday was the greatest experimental philosopher the world has ever seen; and I will add the opinion, that the progress of future research will tend, not to dim or to diminish, but to enhance and glorify the labours of this mighty investigator.” Two electrical units (for capacitance and charge) were named after Michael Faraday to honor his accomplishments: Farad (F) is the SI unit of electric capacitance. Very early in the study of electricity scientists discovered that a pair of conductors separated by an insulator can store a much larger charge than an isolated conductor can store. The better the insulator, the larger the charge that the conductors can hold. This property of a circuit is called capacitance, and it is measured in farads. One farad is defined as the ability to store one coulomb of charge per volt of potential difference between the two conductors. This is a natural definition, but the unit it defines is very large.

In practical circuits, capacitance is often measured in microfarads, nanofarads, or sometimes even in picofarads (10-12 farad, or trillionths of a farad). Faraday (Fd) is a unit of electric charge. In a process called electrolysis, chemists separate the components of a dissolved chemical compound by passing an electric current through the compound. The components are deposited at the electrodes, where the current enters or leaves the solution. The British electrochemist and physicist Michael Faraday determined that the same amount of charge is needed to deposit one mole of any element or ion of valence one (meaning that each molecule of the ion has either one too many or one too few electrons). This amount of charge, equal to about 96.4853 kilocoulombs, became known as Faraday’s constant. Later, it was adopted as a convenient unit for measuring the charges used in electrolysis. One faraday is equal to the product of Avogadro’s number and the charge (1 e) on a single electron.

Michael Faraday - Contributions to Physics and Chemistry Michael Faraday Michael Faraday, an English chemist and physicist was one of the greatest scientists who contributed to the fields of electromagnetism and electrochemistry. His concepts on electromagnetic induction, diamagnetism and laws of electrolysis are yet to be disproved. Michael Faraday Research in chemistry led him to discover benzene and develop the earliest form of a Bunsen burner. Faraday is reputed to be the first and foremost Fullerian Professor of Chemistry appointed at the Royal Institute of Great Britain. Faraday was born in a very poor family on 22nd September 1791 in Newington Butts which is now forms a part of the London Borough of Southwark. He had three other siblings and hence was deprived of basic necessity on account of his family's poor status. So he had to take efforts to educate himself. He worked as an apprentice to a bookseller for seven years and during this period he read many books that helped him to develop a thirst for science. At the age of twenty, Faraday started attending lectures given by notable people like Humphry Davy and John Tatum.

He worked as Davy's secretary and later on was appointed as Chemical Assistant at the Royal Institution in 1813. Faraday's trips with Davy helped him learn about many European scientists and develop sound scientific ideas. Faraday began his research in chemistry under Humphry Davy. During this time Faraday carried out many experiments and made new discoveries in the field of chemical science. His works include identifying new chlorides of carbon, liquefying gases and the invention of the first Bunsen burner (before it was given this name). He also discovered the compound benzene and found out the chemical structure of chlorine clathrate hydrate, a substance found out by Davy in 1810. Faraday's laws of electrolysis are widely accepted even today. His extensive research in chemistry also led to the introduction of a new field called nanoscience. Faraday was well known for his research activities in magnetism and electricity. Faraday worked with several other scientists and discovered several concepts related to electromagnetism. After the death of his mentor, Humphry Davy, he began extensive research that led him to discover electromagnetic induction. His greatest discovery was a phenomenon known as mutual inductance.

By this he showed that an electric field can be produced from an active magnetic field. Using this same principle, Faraday built the dynamo, an earlier form of the present day generator (or electric motor). As he was nearing his end, he proposed various concepts on electromagnetic flux density (not the flux capacitor, however). Faraday also introduced what is now known as Diamagnetism and the Faraday cage, which are concerned with the properties of electricity. James Clerk Maxwell adopted the theories of Faraday and translated them into a set of equations that formed the basis of all electromagnetic theory. Apart from scientific research activities, he also undertook numerous complex projects for several private concerns and also for the British government. He also involved himself in several projects related to the construction of light houses and protecting the bottom of ships from getting corroded. Faraday also made efforts to conserve the environment and spread education. Faraday was honored with a Doctorate in Civil Law by the University of Oxford in 1832. He was appointed as a foreign member to the Royal Swedish Academy of Sciences in 1838. Faraday passed away on 25th August 1857 in his residence at Hampton court.

Even after his death he is still remembered as one of the best scientists to have contributed to the fields of physics and chemistry. Rumor has it ï¿½ Rumor has it that Faraday also invented the first crude stun gun that he used on occasion at night in the taverns he frequented. When someone was in his particular barstool he would zap them from behind to get them to move. Also when his tab at the tavern became too high, he would zap the bartender unconscious, zero out the tab and buy a round of beer on the house. Since most drunkards didn't know what electricity was at that time, Faraday and his stun gun was perceived akin to a wizard with his magic wand, at least in the beer-drinking community. Written by Kevin Lepton History History [ Next >> ] They wrote the history of electricity None of the industrial and domestic applications which ensure our efficiency at work and well-being in the home would exist without the genius of researchers who, over the past two hundred years, have constantly broken new ground in the exploitation of energy.

Let us remember some of these major figures in the history of electricity : 1820 - Christian Oersted, a Danish physicist, discovered the existence of the magnetic field created by electric currents. 1825 - Sturgeon (Great Britain) invented the electromagnet. 1833 - Michael Faraday, an English physicist, developed the theory of electrostatic influence, defined the laws of electrolysis and discovered electromagnetic induction. 1837 - Samuel Morse, a US physicist, invented the electric telegraph and its alphabet. 1859 - Gaston Planté, a French physicist, built the first electric battery. 1866 - Werner von Siemens (Germany), author of a remarkable series of studies on electricity used for the production of power, developed the electric dynamo based on the research of Wheatstone and Varley (Great Britain). 1868 - Zénobe Gramme, a Belgian electrician, invented the first industrial dynamo permitting the production of an electric current. 1873 - Aristide Bergès, a French engineer, first generated hydroelectric power. 1877 - Invention of electric welding.

1878 - Thomas Edison, the US physicist, invented a number of electrical devices, including the light bulb. 1879 - Siemens (Germany) built, for the Berlin Exhibition, the first electric locomotive pulling a train of wagons for passenger transport. 1881 - Siemens (Germany) built the first electric tramway line in Berlin. 1883 - Lucien Goulard (France) and Dixon Gibbs (England), both engineers, developed what is considered to be the forerunner of the "transformer". 1885 - The Ganz Company patented the "electric transformer", following joint research by the Hungarian engineers Zipernowski-Deri and Blathy. 1887 - Heinrich Hertz, a German physicist, discovered electric or Hertzian waves, together with the photo-electric effect. 1889 - von Delivo Dobroewiski (Germany) developed and patented the "triphase transformer". 1890 - Marey (France) developed a device able to take up to 16 photos a second. 1892 - Edison created his kinetoscope able to show a succession of images creating the impression of movement.

1893 - Elster and Geitel (Germany) developed the photoelectric cell. 1895 - The Lumière brothers (France) presented their device for film projection. 1898 - First electric power station opened in Oisquerecq with a power of more than 100 kW. (The present installed power in Belgium is 15,339,00 kW). CEBEC. 1923-1998 75 years in the service of the quality of life 75 years of professional activity to ensure safe and efficient human activity with the comfort of electricity in the home, at work and during leisure activities. This reality is the result of 75 years of constant efforts to study every product and device and to define standards ensuring safety of use and quality of components. 75 years devoted to controlling tens of thousands of products and awarding the CEBEC quality mark. Homage to our predecessors Back at the very beginning of the century, our predecessors pooled their professionalism to ensure the efficient and problem-free comfort of electricity. They formed companies, drew up safety and quality standards, and created the bodies to ensure their application.

The Belgian Electrotechnical Committee Founded in 1884, the Belgian Society of Electricians (SBE) already had 230 members in 1885 and experienced growing success. It defined its mission in 1906 and in 1909 founded the Belgian Electrotechnical Committee (CEB), charged with the following tasks : To define safety and quality standards for electrotechnical equipment To ensure compliance of equipment with its standards by means of detailed examinations and testing by an approved laboratory. To award quality marks to equipment manufactured according to its recommendations. ... Some famous names... PLATEAU Joseph (1801-1883). Physicist. Developed the phenomenon of retinal retention and invented (1832) the phenakistoscope, a device which was the direct forerunner of the cinema. MELSENS Louis (1814-1886). Physicist and chemist. Perfected the lightning rod by applying the principle of the Faraday cage. First president of the Belgian Electrotechnical Committee. LENOIR Etienne (1822-1900). Belgian born, naturalised French engineer.

Produced and operated the first internal combustion engine by air expansion following the combustion of ignited gases which permitted the production of a four-stroke engine. GRAMME Zénobe (1826-1901). Self-taught physicist. Won worldwide acclaim as inventor of the dynamo. MONTEFIORE-LEVI (1832-1906). Engineer. Senator for Liège from 1882 to 1901. Founder of the Belgian Montefiore Institute which trains civil electrical engineers. VAN MONCKHOVEN Désiré (1834-1882). Chemist. Manufactured photographic plates which met with great success. SOLVAY Ernest (1882-1922). Chemist and industrialist. His discovery of caustic soda was industrially exploited by the Société Solvay et Cie which became one of the worldwide giants of the chemical industry. FIEVEZ Charles (1844-1890). Engineer. One of the 19th century's great astronomers. Studied the solar spectrum.

BRANLY Edouard (1844-1940). Inventor of one of the first cableless telegraph systems. Elected honorary member of the Belgian Society of Electricians in 1932. [ Next >> ] Michael Faraday | British physicist and chemist | Britannica.com British physicist and chemist Michael Faraday, (born September 22, 1791, Newington , Surrey , England —died August 25, 1867, Hampton Court, Surrey), English physicist and chemist whose many experiments contributed greatly to the understanding of electromagnetism . Michael Faraday, oil on canvas by Thomas Phillips, 1841–42; in the National Portrait Gallery, … Courtesy of The National Portrait Gallery, London Faraday , who became one of the greatest scientists of the 19th century, began his career as a chemist. He wrote a manual of practical chemistry that reveals his mastery of the technical aspects of his art, discovered a number of new organic compounds , among them benzene , and was the first to liquefy a “permanent” gas (i.e., one that was believed to be incapable of liquefaction).

His major contribution, however, was in the field of electricity and magnetism . He was the first to produce an electric current from a magnetic field , invented the first electric motor and dynamo , demonstrated the relation between electricity and chemical bonding , discovered the effect of magnetism on light , and discovered and named diamagnetism , the peculiar behaviour of certain substances in strong magnetic fields. He provided the experimental, and a good deal of the theoretical, foundation upon which James Clerk Maxwell erected classical electromagnetic field theory. Early life Michael Faraday was born in the country village of Newington, Surrey, now a part of South London. His father was a blacksmith who had migrated from the north of England earlier in 1791 to look for work. His mother was a country woman of great calm and wisdom who supported her son emotionally through a difficult childhood. Faraday was one of four children, all of whom were hard put to get enough to eat, since their father was often ill and incapable of working steadily. Faraday later recalled being given one loaf of bread that had to last him for a week. The family belonged to a small Christian sect, called Sandemanians , that provided spiritual sustenance to Faraday throughout his life.

It was the single most important influence upon him and strongly affected the way in which he approached and interpreted nature. Michael Faraday. © iStockphoto/Thinkstock Faraday received only the rudiments of an education, learning to read, write, and cipher in a church Sunday school. At an early age he began to earn money by delivering newspapers for a book dealer and bookbinder, and at the age of 14 he was apprenticed to the man. Unlike the other apprentices, Faraday took the opportunity to read some of the books brought in for rebinding. The article on electricity in the third edition of the Encyclopædia Britannica particularly fascinated him. Using old bottles and lumber, he made a crude electrostatic generator and did simple experiments. He also built a weak voltaic pile with which he performed experiments in electrochemistry . Britannica Stories Cheetahs Face Extinction Risk Faraday’s great opportunity came when he was offered a ticket to attend chemical lectures by Sir Humphry Davy at the Royal Institution of Great Britain in London . Faraday went, sat absorbed with it all, recorded the lectures in his notes, and returned to bookbinding with the seemingly unrealizable hope of entering the temple of science .

He sent a bound copy of his notes to Davy along with a letter asking for employment, but there was no opening. Davy did not forget, however, and, when one of his laboratory assistants was dismissed for brawling, he offered Faraday a job. Faraday began as Davy’s laboratory assistant and learned chemistry at the elbow of one of the greatest practitioners of the day. It has been said, with some truth, that Faraday was Davy’s greatest discovery. When Faraday joined Davy in 1812, Davy was in the process of revolutionizing the chemistry of the day. Antoine-Laurent Lavoisier , the Frenchman generally credited with founding modern chemistry, had effected his rearrangement of chemical knowledge in the 1770s and 1780s by insisting upon a few simple principles. Among these was that oxygen was a unique element , in that it was the only supporter of combustion and was also the element that lay at the basis of all acids .

Davy, after having discovered sodium and potassium by using a powerful current from a galvanic battery to decompose oxides of these elements, turned to the decomposition of muriatic (hydrochloric) acid , one of the strongest acids known. The products of the decomposition were hydrogen and a green gas that supported combustion and that, when combined with water , produced an acid. Davy concluded that this gas was an element, to which he gave the name chlorine , and that there was no oxygen whatsoever in muriatic acid. Acidity, therefore, was not the result of the presence of an acid-forming element but of some other condition. What else could that condition be but the physical form of the acid molecule itself? Davy suggested, then, that chemical properties were determined not by specific elements alone but also by the ways in which these elements were arranged in molecules. In arriving at this view he was influenced by an atomic theory that was also to have important consequences for Faraday’s thought. This theory, proposed in the 18th century by Ruggero Giuseppe Boscovich , argued that atoms were mathematical points surrounded by alternating fields of attractive and repulsive forces.

A true element comprised a single such point, and chemical elements were composed of a number of such points, about which the resultant force fields could be quite complicated. Molecules, in turn, were built up of these elements, and the chemical qualities of both elements and compounds were the results of the final patterns of force surrounding clumps of point atoms. One property of such atoms and molecules should be specifically noted: they could be placed under considerable strain, or tension, before the “bonds” holding them together were broken. These strains were to be central to Faraday’s ideas about electricity . Britannica Lists & Quizzes Editor Picks: Exploring 10 Types of Basketball Movies Faraday’s second apprenticeship, under Davy, came to an end in 1820. By then he had learned chemistry as thoroughly as anyone alive. He had also had ample opportunity to practice chemical analyses and laboratory techniques to the point of complete mastery, and he had developed his theoretical views to the point that they could guide him in his researches. There followed a series of discoveries that astonished the scientific world. Ins and Outs of Chemistry Faraday achieved his early renown as a chemist.

His reputation as an analytical chemist led to his being called as an expert witness in legal trials and to the building up of a clientele whose fees helped to support the Royal Institution. In 1820 he produced the first known compounds of carbon and chlorine , C 2Cl6 and C2Cl4. These compounds were produced by substituting chlorine for hydrogen in “olefiant gas” ( ethylene ), the first substitution reactions induced. (Such reactions later would serve to challenge the dominant theory of chemical combination proposed by Jöns Jacob Berzelius .) In 1825, as a result of research on illuminating gases, Faraday isolated and described benzene . In the 1820s he also conducted investigations of steel alloys , helping to lay the foundations for scientific metallurgy and metallography . While completing an assignment from the Royal Society of London to improve the quality of optical glass for telescopes , he produced a glass of very high refractive index that was to lead him in 1845 to the discovery of diamagnetism .

In 1821 he married Sarah Barnard, settled permanently at the Royal Institution, and began the series of researches on electricity and magnetism that were to revolutionize physics . Chemical chest belonging to Michael Faraday, 19th century. Science Museum London Facebook Twitter YouTube Instagram Pinterest In 1820 Hans Christian Ørsted had announced the discovery that the flow of an electric current through a wire produced a magnetic field around the wire. André-Marie Ampère showed that the magnetic force apparently was a circular one, producing in effect a cylinder of magnetism around the wire. No such circular force had ever before been observed, and Faraday was the first to understand what it implied. If a magnetic pole could be isolated, it ought to move constantly in a circle around a current-carrying wire. Faraday’s ingenuity and laboratory skill enabled him to construct an apparatus that confirmed this conclusion. This device, which transformed electrical energy into mechanical energy, was the first electric motor . This discovery led Faraday to contemplate the nature of electricity. Unlike his contemporaries, he was not convinced that electricity was a material fluid that flowed through wires like water through a pipe.

Instead, he thought of it as a vibration or force that was somehow transmitted as the result of tensions created in the conductor. One of his first experiments after his discovery of electromagnetic rotation was to pass a ray of polarized light through a solution in which electrochemical decomposition was taking place in order to detect the intermolecular strains that he thought must be produced by the passage of an electric current. During the 1820s he kept coming back to this idea, but always without result. Trending Topics Srinivasa Ramanujan In the spring of 1831, Faraday began to work with Charles (later Sir Charles) Wheatstone on the theory of sound , another vibrational phenomenon. He was particularly fascinated by the patterns (known as Chladni figures) formed in light powder spread on iron plates when these plates were thrown into vibration by a violin bow. Here was demonstrated the ability of a dynamic cause to create a static effect, something he was convinced happened in a current-carrying wire. He was even more impressed by the fact that such patterns could be induced in one plate by bowing another nearby. Such acoustic induction is apparently what lay behind his most famous experiment.

On August 29, 1831, Faraday wound a thick iron ring on one side with insulated wire that was connected to a battery. He then wound the opposite side with wire connected to a galvanometer . What he expected was that a “wave” would be produced when the battery circuit was closed and that the wave would show up as a deflection of the galvanometer in the second circuit. He closed the primary circuit and, to his delight and satisfaction, saw the galvanometer needle jump. A current had been induced in the secondary coil by one in the primary. When he opened the circuit, however, he was astonished to see the galvanometer jump in the opposite direction. Somehow, turning off the current also created an induced current, equal and opposite to the original current, in the secondary circuit. This phenomenon led Faraday to propose what he called the “electrotonic” state of particles in the wire, which he considered a state of tension. A current thus appeared to be the setting up of such a state of tension or the collapse of such a state. Although he could not find experimental evidence for the electrotonic state, he never entirely abandoned the concept, and it shaped most of his later work.

In the fall of 1831, Faraday attempted to determine just how an induced current was produced. His original experiment had involved a powerful electromagnet created by the winding of the primary coil. He now tried to create a current by using a permanent magnet . He discovered that when a permanent magnet was moved in and out of a coil of wire, a current was induced in the coil. Magnets, he knew, were surrounded by forces that could be made visible by the simple expedient of sprinkling iron filings on a card held over them. Faraday saw the “lines of force” thus revealed as lines of tension in the medium, namely air, surrounding the magnet, and he soon discovered the law determining the production of electric currents by magnets: the magnitude of a current was dependent upon the number of lines of force cut by the conductor in unit time. He immediately realized that a continuous current could be produced by rotating a copper disk between the poles of a powerful magnet and taking leads off the disk’s rim and centre. The outside of the disk would cut more lines than would the inside, and there would thus be a continuous current produced in the circuit linking the rim to the centre. This was the first dynamo .

It was also the direct ancestor of electric motors , for it was only necessary to reverse the situation, to feed an electric current to the disk, to make it rotate. Theory of electrochemistry While Faraday was performing these experiments and presenting them to the scientific world, doubts were raised about the identity of the different manifestations of electricity that had been studied. Were the electric “fluid” that apparently was released by electric eels and other electric fishes, that produced by a static electricity generator, that of the voltaic battery , and that of the new electromagnetic generator all the same? Or were they different fluids following different laws? Faraday was convinced that they were not fluids at all but forms of the same force, yet he recognized that this identity had never been satisfactorily shown by experiment. For this reason he began, in 1832, what promised to be a rather tedious attempt to prove that all electricities had precisely the same properties and caused precisely the same effects. The key effect was electrochemical decomposition. Voltaic and electromagnetic electricity posed no problems, but static electricity did. As Faraday delved deeper into the problem, he made two startling discoveries.

First, electrical force did not, as had long been supposed, act at a distance upon chemical molecules to cause them to dissociate. It was the passage of electricity through a conducting liquid medium that caused the molecules to dissociate, even when the electricity merely discharged into the air and did not pass into a “pole” or “centre of action” in a voltaic cell. Second, the amount of the decomposition was found to be related in a simple manner to the amount of electricity that passed through the solution. These findings led Faraday to a new theory of electrochemistry . The electric force, he argued, threw the molecules of a solution into a state of tension (his electrotonic state). When the force was strong enough to distort the fields of forces that held the molecules together so as to permit the interaction of these fields with neighbouring particles, the tension was relieved by the migration of particles along the lines of tension, the different species of atoms migrating in opposite directions. The amount of electricity that passed, then, was clearly related to the chemical affinities of the substances in solution.

These experiments led directly to Faraday’s two laws of electrochemistry: (1) The amount of a substance deposited on each electrode of an electrolytic cell is directly proportional to the quantity of electricity passed through the cell. (2) The quantities of different elements deposited by a given amount of electricity are in the ratio of their chemical equivalent weights. Faraday’s work on electrochemistry provided him with an essential clue for the investigation of static electrical induction . Since the amount of electricity passed through the conducting medium of an electrolytic cell determined the amount of material deposited at the electrodes, why should not the amount of electricity induced in a nonconductor be dependent upon the material out of which it was made? In short, why should not every material have a specific inductive capacity ? Every material does, and Faraday was the discoverer of this fact. Michael Faraday (left) and John Frederic Daniell. © Photos.com/Thinkstock By 1839 Faraday was able to bring forth a new and general theory of electrical action. Electricity, whatever it was, caused tensions to be created in matter.

When these tensions were rapidly relieved (i.e., when bodies could not take much strain before “snapping” back), then what occurred was a rapid repetition of a cyclical buildup, breakdown, and buildup of tension that, like a wave, was passed along a substance. Such substances were called conductors . In electrochemical processes the rate of buildup and breakdown of the strain was proportional to the chemical affinities of the substances involved, but again the current was not a material flow but a wave pattern of tensions and their relief. Insulators were simply materials whose particles could take an extraordinary amount of strain before they snapped. Electrostatic charge in an isolated insulator was simply a measure of this accumulated strain. Thus, all electrical action was the result of forced strains in bodies. The strain on Faraday of eight years of sustained experimental and theoretical work was too much, and in 1839 his health broke down. For the next six years he did little creative science. Not until 1845 was he able to pick up the thread of his researches and extend his theoretical views. Later life Since the very beginning of his scientific work, Faraday had believed in what he called the unity of the forces of nature.

By this he meant that all the forces of nature were but manifestations of a single universal force and ought, therefore, to be convertible into one another. In 1846 he made public some of the speculations to which this view led him. A lecturer, scheduled to deliver one of the Friday evening discourses at the Royal Institution by which Faraday encouraged the popularization of science, panicked at the last minute and ran out, leaving Faraday with a packed lecture hall and no lecturer. On the spur of the moment, Faraday offered “ Thoughts on Ray Vibrations. ” Specifically referring to point atoms and their infinite fields of force, he suggested that the lines of electric and magnetic force associated with these atoms might, in fact, serve as the medium by which light waves were propagated . Many years later, Maxwell was to build his electromagnetic field theory upon this speculation. Michael Faraday, c. 1860. © Photos.com/Thinkstock When Faraday returned to active research in 1845, it was to tackle again a problem that had obsessed him for years, that of his hypothetical electrotonic state. He was still convinced that it must exist and that he simply had not yet discovered the means for detecting it.

Once again he tried to find signs of intermolecular strain in substances through which electrical lines of force passed, but again with no success. It was at this time that a young Scot, William Thomson (later Lord Kelvin) , wrote Faraday that he had studied Faraday’s papers on electricity and magnetism and that he, too, was convinced that some kind of strain must exist. He suggested that Faraday experiment with magnetic lines of force, since these could be produced at much greater strengths than could electrostatic ones. Michael Faraday lecturing on electricity and magnetism, Royal Institution, London, Jan. 23, 1846. © Photos.com/Thinkstock Faraday took the suggestion, passed a beam of plane-polarized light through the optical glass of high refractive index that he had developed in the 1820s, and then turned on an electromagnet so that its lines of force ran parallel to the light ray. This time he was rewarded with success. The plane of polarization was rotated, indicating a strain in the molecules of the glass. But Faraday again noted an unexpected result.

When he changed the direction of the ray of light, the rotation remained in the same direction, a fact that Faraday correctly interpreted as meaning that the strain was not in the molecules of the glass but in the magnetic lines of force. The direction of rotation of the plane of polarization depended solely upon the polarity of the lines of force; the glass served merely to detect the effect. This discovery confirmed Faraday’s faith in the unity of forces, and he plunged onward, certain that all matter must exhibit some response to a magnetic field. To his surprise he found that this was in fact so, but in a peculiar way. Some substances, such as iron , nickel , cobalt , and oxygen , lined up in a magnetic field so that the long axes of their crystalline or molecular structures were parallel to the lines of force; others lined up perpendicular to the lines of force. Substances of the first class moved toward more intense magnetic fields; those of the second moved toward regions of less magnetic force. Faraday named the first group paramagnetics and the second diamagnetics . After further research he concluded that paramagnetics were bodies that conducted magnetic lines of force better than did the surrounding medium, whereas diamagnetics conducted them less well.

By 1850 Faraday had evolved a radically new view of space and force. Space was not “nothing,” the mere location of bodies and forces, but a medium capable of supporting the strains of electric and magnetic forces. The energies of the world were not localized in the particles from which these forces arose but rather were to be found in the space surrounding them. Thus was born field theory. As Maxwell later freely admitted, the basic ideas for his mathematical theory of electrical and magnetic fields came from Faraday; his contribution was to mathematize those ideas in the form of his classical field equations . About 1855, Faraday’s mind began to fail. He still did occasional experiments, one of which involved attempting to find an electrical effect of raising a heavy weight, since he felt that gravity , like magnetism, must be convertible into some other force, most likely electrical. This time he was disappointed in his expectations, and the Royal Society refused to publish his negative results. More and more, Faraday sank into senility. Queen Victoria rewarded his lifetime of devotion to science by granting him the use of a house at Hampton Court and even offered him the honour of a knighthood.

Faraday gratefully accepted the cottage but rejected the knighthood; he would, he said, remain plain Mr. Faraday to the end. He died in 1867 and was buried in Highgate Cemetery, London, leaving as his monument a new conception of physical reality. Michael Faraday, 1881. HistoryMole Timeline: Michael Faraday (1791-1867) Michael Faraday (1791-1867) More : 27 Oct 1813 CEHumphrey Davy arrived in Paris with his wife and his assitant Michael Faraday. He received special dispensation from Napoleon to travel across France from 1813 to 1815 and with Faraday he travelled abroad investigating his theory of volcanic action. Note 1: Events described with text like this have been entered from one source but have not yet been verified against a subsequent source ( Explain ). Note 2: The events are sorted in semi-chronological order according to what is factually known about the date of the event ( Explain ).

Note 3: Faraday - definition of Faraday by The Free Dictionary Faraday - definition of Faraday by The Free Dictionary (făr′ə-dā′) n. A measure of the electric charge carried by one mole of electrons, used in electrolysis as the quantity of charge required to deposit or liberate one gram equivalent weight of a substance, approximately 9.6494 × 104 coulombs. [After Michael Faraday.] (ˈfærəˌdeɪ) n (Biography) Michael. 1791–1867, English physicist and chemist who discovered electromagnetic induction, leading to the invention of the dynamo. He also carried out research into the principles of electrolysis faraday (ˈfærəˌdeɪ) n (Units) a quantity of electricity, used in electrochemical calculations, equivalent to unit amount of substance of electrons. It is equal to the product of the Avogadro number and the charge on the electron and has the value 96 487 coulombs per mole. Symbol: F [C20: named after Michael Faraday] Far•a•day

Question: Which English chemist and physicist invented the dynamo?
Answer: Michael Faraday